Université Grenoble Alpes, CEA, Leti, CLINATEC, F-38000 Grenoble, France.
J Neural Eng. 2019 Nov 19;16(6):066047. doi: 10.1088/1741-2552/ab3836.
The goal of this study was to evaluate the long-term behavior of the surface electrode through electrochemical characterization and follow-up of implanted parylene/platinum microelectrodes.
To this aim, we designed and manufactured specific planar electrodes for cortical implantation for a rat model. This work was included in the INTENSE project, one of the goals of which was to prove the feasibility of selective neural recording or stimulation with cuff electrodes around the vagus nerve.
After a 12-week implantation in a rat model, we can report that these microelectrodes have withstood in vivo use. Regarding the biocompatibility of the electrodes (materials and manufacturing process), no adverse effect was reported. Indeed, after the three-month implantation, we characterized limited tissue reaction beneath the electrodes and showed an increase and a stabilization of their impedance. Interestingly, the follow-up of the electrochemical impedance combined with electrical stimulation highlighted a drop in the impedance up to 60% at 1 kHz after ten minutes of electrical stimulation at 110 Hz.
This study gives evidence of the biocompatibility of the parylene platinum contact array designed for the project and confirms the effect of stimulation on the contact impedance.
本研究旨在通过电化学特性分析和植入的聚对二甲苯/铂微电极的后续随访，评估表面电极的长期性能。
为此，我们为大鼠模型设计并制造了特定的皮层植入用平面电极。这项工作包含在 INTENSE 项目中，该项目的目标之一是证明使用套在迷走神经周围的 cuff 电极进行选择性神经记录或刺激的可行性。
在大鼠模型中进行了 12 周的植入后，我们可以报告这些微电极已经经受住了体内使用。关于电极的生物相容性（材料和制造工艺），没有报告不良反应。事实上，在三个月的植入后，我们在电极下方观察到有限的组织反应，并显示出其阻抗的增加和稳定。有趣的是，电化学阻抗的后续监测结合电刺激表明，在以 110 Hz 进行 10 分钟的 1 kHz 电刺激后，阻抗下降了 60%。
本研究证明了为该项目设计的聚对二甲苯铂接触阵列的生物相容性，并证实了刺激对接触阻抗的影响。
